Switch construction



J. J. MlKOS SWITCH CONSTRUCTION Dec. 22, 1959 6 Sheets-Sheet 1 Filed Nov. 18, 1957 INVENTOR. John J fdia W Dec. 22, 1959 J. J. MIKOS 2,918,556

SWITCH CONSTRUCTION Filed Nov. 18, 1957 6 Sheets-Sheet 2 IN VEN TOR.

Dec. 22, 1959 .1. J. MIKOS 5 SWITCH CONSTRUCTION Filed Nov. 18, 1957 s Sheets-Sheet 3' Dec. 22, 1959 J. J. MIKOS 2,918,556

SWITCH CONSTRUCTION Filed Nov. 18, 1957 6 Sheets-Sheet 4 IN V EN TOR.

\folzn J M1160$ Dec. 22, 1959 J. J. MIKOS SWITCH CONSTRUCTION 6 Sheets-Sheet 5 Filed NOV. 18, 1957 lNVEI IT OR. J/Vuma,

Dec. 22, 1959 J. J. MIKOS 2,918,556

SWITCH CONSTRUCTION Filed Nov. 18, 1957 6 Sheets-Sheet 6 United States Patent Ofitice 2,918,556 Patented Dec. 22, 1959 2,918,556 SWITCH CONSTRUCTION John J. Mikos, Highland Park, Ill., assignor to S & C

Electric Company, Chicago, 11]., a corporation of Delaware Application November 18, 1957, Serial No. 697,264

32 Claims. (Cl. 200-169) This invention relates, generally, to switches and it has 5133111611121! relation to high voltage disconnecting switches. "*This application is a continuation-in-part of application Ser. No..'.638,742, filed February 7, 1957, now abandoned.

It is customary to employ a disconnecting switch for isolating a circuit. Conventional disconnecting switches are intended to be opened only when no current is flow- .--:ing in the circuit. Since such switches are not provided with any means for extinguishing the are drawn on openfjsing load, they should not be operated under such con- -dltlOIlS. However, it is desirable to provide for opening z'such switches under load and it is to the provision of :;means therefor and the particular adaptation of a dist. connecting switch thereto that this invention is addressed. Among the objects of this invention are: To construct :a disconnecting switch in such manner that it can be (operated by an auxiliary circuit interrupter to open a :circuit under load without external arcing; to provide :such an arrangement that the switch blade will be swung "to a position, when the circuit is opened by the auxiliary \cir-cuit interrupter, in which the voltage normally applied to the switch will be incapable of restriking an arc in air externally of the auxiliary circuit interrupter; to provide for guiding the switch blade into engagement with a contact member and for anchoring a part of the auxiliary circuit interrupter to open the switch without external arcing; to "latch the switch blade in closed position and to pry it out of such position with the latch and operating mechanism therefor being carried by a pair of switchblade members and located between the switch contact and the pivot of the switch blade; to provide a maximum area of contact between a channel base supporting the switch insulators and the cross arms on which the base is mounted; and to provide a removable stop pin in the switch blade extending through an aperture .therein adjacent the pivot end together with a spring pressed member in the hinge member for entering this aperture when the pin is removed for holding the switch blade in predetermined open position.

Additional objects of this invention are: To provide improved biasing action in the latch mechanism; to apply a relatively light spring force against the latch that prevents opening of the switch blade and a relatively heavy spring force against the pull ring that moves the latch to unlatched position; to provide two springs for this purpose reacting between the switch blade and the latch and pull ring respectively; to pivotally mount the pull :ring on the switch blade and to shape the eye of the pull ring such that a pull can be applied thereto from any position through a relatively wide angle to exert a turning moment about its pivot suflicient to unlatch the switch blade; to locate the portions of the pull ring on the side away from its pivot axis at an acute angle to the longitudinal axis of the switch blade in order to facilitate the movement of the engaging prong of a live line tool to a position where the moment exerted thereby about the pivot axis of the pull ring is increased; and 1 ofiset theeye of the pull ring from its pivot axis and thereby increase the range of possible applications of the live line tool for unlatching the switch blade.

Other objects of this invention will, in part, be obvious and in part appear hereinafter.

This invention is disclosed in the embodiments thereof shown in the accompanying drawings and it comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the constructions hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of this invention, reference can be had to the following detailed description, taken together with the accompanying drawings, in which:

Figure 1 is a view, in side elevation, of a disconnecting switch in which the present invention is embodied mounted in a vertical position on a pair of cross arms which are positioned one above the other, the switch being arranged for operation through the agency of an auxiliary circuit interrupter of the type illustrated in application Serial No. 569,909, filed March 6, 1956, now Patent No. 2,816,981, issued December 17, 1957;

Figure 2 is a view, similar to Figure 1, showing the switch in the partly open position with the auxiliary circuit interrupter extended to a position slightly in advance of the position in which the separable contacts therein are opened to interrupt the shunt circuit bridging the disconnecting switch gap;

Figure 3 is a view, in side elevation, showing the disconnecting switch in closed position and underhung with respect to the cross arms;

Figure 4 is a view, similar to Figure 3, and showing the disconnecting switch and auxiliary circuit interrupter in the same relative positions as illustrated for Figure 2;

Figure 5 is a view, in front elevation, showing the disconnecting switch at an enlarged scale;

Figure 6 is a view, in side elevation, of the switch shown in Figure 5;

Figure 7 is a top plan view of the switch shown in Figures 5 and 6;

Figure 8 is a view, partly in elevation and partly in longitudinal section, shown at an enlarged scale, showing the details of construction of the switch blade;

Figure 9 is a view, in side elevation, certain parts being broken away, of the contact member which forms a part of the upper terminal assembly;

Figure 10 is a detail sectional view, at an enlarged scale, taken generally along the line 10--10 of Figure 6;

Figure 11 is an enlarged view, taken generally along the line 1111 of Figure 5, and showing how the switch blade members are guided into the switch closed position even though the switch blade may initially be mis aligned with respect to the contact member to be engaged thereby;

Figure 12 is a view, partly in front elevation and partly in longitudinal section of the switch blade, showing details of construction of a modified latch and pull ring assembly;

Figure 13 is a view, in side elevation, of the upper end of the switch blade and the upper terminal assembly in which the modified construction is employed;

Figure 14 is a view, partly in side elevation and partly in section, of the contact member which forms a part of the upper terminal assembly shown in Figure 13;

Figure 15 is a vertical sectional view, taken generally along the line 15-15 of Figure 12, showing the relation of the contact member, latch and pull ring in the fully latched position and the switch blade fully closed;

Figure 16 is a view, similar to Figure 15, showing the relation of the contact member, latch and pull ring during the unlatching of the switch blade and its movement from the fully closed position.

Figure l7 is a view, similar to Figure 15, taken generally along the line 1717 of Figure 12;

Figure 18 is a view, similar to Figure 17 with the parts in the positions shown for Figure 16; and

Figure 19 is a view, similar to Figure 16, showing the relation of the latch and pull ring when the latter has been swung to the limit of its travel relative to the switch blade in the unlatching direction.

Referring now particularly to Figures 1 to 4 of the drawings, it will be observed that the reference character designates wood supports or cross arms. In Figures 1 and 2 the wood supports or cross arms 10 are positioned one above the other while in Figures 3 and 4 they are positioned in the same horizontal plane. They are arranged for mounting a disconnecting switch assembly, shown generally at 11. In Figures 1 and 2 of the drawings the disconnecting switch assembly 11 is vertically mounted while in Figures 3 and 4 his located in an underhung position.

The disconnecting switch 11 includes a channel base 12 of rolled steel section having a fiat side 13 which bears against the respective sides of the wood supports or cross arms 10. The reason for placing the fiat side 13 in the position described is to provide a large area of contact between the channel base 12 and the wood supports or cross arms 10 inorder to avoid cutting of the supports or cross arms as often is the case when the side flanges 14, rather than the flat side 13, are placed in engagement with the supports or cross arms 10 and clamped thereto. The flat side 13 is clamped to the cross arms 10 by means of clamp bolts 15 and clamps 16 which are located on the opposite sidesof'the wood supports or cross arms 10, as illustrated. I

it is desirable to provide plates 17 transversely of the side flanges 14 in order to support insulators 18 in spaced relation to these flanges. The plates 17 may be secured by any suitable means, such as by welding to the side flanges 14. The insulators 18 may be of the post type, as illustrated, and they are arranged to carry at their outer ends upper and lower terminal assemblies indicated, respectively, 'at 19 and 20. It will be observed that each terminal assembly includes a terminal pad 21 which has projecting therefrom a conductor stop 22 to limit the extent that the conductor connected to the respective terminal assemblies can be moved inwardly. Each terminal pad is provided with a conductor clamp 23 that is arranged to clampingly engage the respective conductor through the agency of the clamp bolts 24. The clamp bolts 24 thread into the respective conductor clamp 23 and their heads 25 are located on the side of the terminal pad 21 adjacent the channel base 12. Since the heads 25 of the clamp-bolts 24 always engage the rear sides of the respective terminal pads 21, these heads always: are located at the same distance from the channel base '12 which ordinarily may be grounded. Thus, with varying sizes of conductors, there is no variation in the distance to ground from the terminal pads 21 as might be the case if the conductor clamp bolts 24 extended from the front side of the terminal pads 21 rearwardly toward the channel base 12. The clamp bolts 24 can be turned independently in the clamps 23 without stripping.

The terminal pad 21'of the lower terminal assembly is provided with an integrally formed outwardly extending hinge member 26 onwhich is pivotally mounted at 27 a switch blade that is indicated, generally, at 28. At its upper end the switch blade 28 is arranged to engage a contact member '29 which extends outwardly from the terminal pad 21 of the upper terminal assembly 19. The details of construction of the hinge member 26, switch blade 28 and contact member 29 will be set forth hereinafter in connection with a consideration of Figures 511 of the drawings. r

As pointedout'hereinbefore, itis desirable toprovide for moving the switch blade 28 toward the open circuit position while it is carrying load current. For this pur' pose an auxiliary circuit interrupter of the separable contact type, shown generally at 32, is provided. Preferably the auxiliary circuit interrupter 32 is constructed as disclosed in the application above referred to. Only a general description of the auxiliary circuit interrupter 32 will be set forth herein since a complete description is found in the application referred to.

The auxiliary circuit interrupter 32 is arranged to be mounted on a live line insulating stick 33 of the type ordinarily found in a linemans truck and adapted to have various types of live line tools clamped thereto. At its upper end the live line stick 33 is provided with a metallic fitting 34 for detachable connection to a metallic strut 35. Near its upper end the strut 35 is provided with a laterally extending prong 36 which is arranged to engage in a pull ring or eye member 37 that is secured to the switch blade '28 at a position remote from the pivot 27. Movable with the strut 35 and the prong 36 is an inner insulating sleeve 38. The sleeve 38 moves within an outer insulating sleeve 39 for the purpose of cocking a spring operated mechanism to effect the separation of contact members in such manner as to interrupt the current flow within the interrupter 32 so that no external arc oc- Near its upper end the outer insulating sleeve 39 is provided with a conducting part including a bow contact member 40 which is arranged to be placed over and connected and anchored to a combination guide and anchor member that is shown generally at 41 and carried by the terminal pad 21 of the upper'terminal assembly 19 at a location below the contact member 29 thereon.

For opening the switch blade 28, the bow contact member 40 is placed over the combination guide and anchor 'member 41, as shown in Figure l, and the prong 36 is caused to engage within the pull ring or eye member 37. This manipulation of the auxiliary circuit interrupter 32 "is accomplished by a lineman through the agency of the 'live line stick 33. Next, he pulls on the live line stick 33 to swing the switch blade 28 to the open position. Since the auxiliary circuit interrupter 32, by its connection to the combination guide and anchor member 41 and to the pull ring or eye member 37, shunts the upper terminal assembly 19' and the switch blade 28, no arc is drawn when the latter moves out of engagement with the contact member 29. Because the bow contact member 40 is held stationary, the outer insulating sleeve 39 to which it is secured likewise is held stationary while the inner insulating sleeve 38 together with the strut 35 and switch blade 23 is pulled outwardly as indicated in Figure 2. This movement is accompanied by a continued' movement of the switch blade 28. Preferably the arrangement is such that the switch blade 28 is moved to a distance, indicated at 42, away from the nearest energized part of the upper terminal assembly 19 including the combination guide and anchor member 41 and bow contact member 40 or parts on the auxiliary circuit interrupter associated therewith such that, after the circuit is interrupted by separation of the contacts within the auxiliary circuit interrupter 32,

the recovery voltage applied at that time between the upper and lower terminal assemblies 19 and 20 of the disconnecting switch assembly 11 will-be incapable of restriking the are between the switch blade 28 and the upper terminal assembly 19 or conducting parts connected thereto including the bow contact member 40. During this operation, the inner insulating sleeve 38 is extended to a distance indicated at 43 at which' time the'operating mechanism is fully cocked and the trigger mechanism is ready to be tripped on a further slight movement of the inner insulating sleeve 38 to separate'the contacts within the auxiliary'circuit interrupter'32 and open the shunt circuit. This relationship of movement of the switch blade 28'and the'inner insulating sleeve 38'with respect attentionshould bepaid to-proper correlation therebeiwenin order to make certain that the switch blade 28 is moved sufliciently far from any energized part of the upperterminal assembly 19 to prevent any likelihood of restriking of the arc externally of the auxiliary circuit in terrupter 32.

After the circuit has been interrupted by the auxiliary circuit interrupter 32, the bow contact member 40 is removed from the combination guide and anchor member 41 by suitable manipulation of the live line stick 33 while the prong 36 still remains in the pull ring or eye member 37. Further manipulation of the live line stick 33 swings the switch blade 28 to the full open position after which the prong 36 can be removed from the pull ring or eye member 37 by further manipulation of the live line stick 33.

Figure 1 shows a typical position of the live line stick 33 and circuit interrupter 32 for opening the switch blade 28 of a disconnecting switch assembly 11 mounted in a vertical position. The arrangement is such that the bow contact member 40 first is applied over the combination guide and anchor member 4i. Then the live line stick 33 is manipulated to position the prong 36 within an opening 37' of the pull ring or eye member 37.

The construction of the pull ring or eye member 37 is such that the same disconnecting switch assembly 11 can be mounted in the underhung position as shown in Figure 3. Here it will be observed that the live line stick 33 and auxiliary circuit interrupter 32 ordinarily will be applied by the lineman in a plane further away from the switch blade 28 than is the case for the vertical position. For the underhung mounting the lineman will ordinarily be located in a plane more nearly at right angles to the switch blade 28 than is the case for the vertical mounting shown in Figure 1. In order to facilitate the insertion of the prong 36 in the opening 37' of the pull ring or eye member 37, the opening is elongated as shown and is generally parallel to the switch blade 28. This, together with the proper positioning of the combination guide and anchor member 41, facilitates placing of the auxiliary circuit interrupter 32 in the shunt position regardless of whether the disconnecting switch assembly 11 is mounted in a vertical position or in a horizontal underhung position. Also, it will be understood that the auxiliary circuit interrupter 32 and the live line stick 33 may be applied by the lineman further away from the switch blade 28 toward a vertical position than is shown in Figure 3. The particular position chosen by the lineman Will depend upon the height of the disconnecting switch assembly 11 above ground or the position of the lineman, location of other apparatus and other factors.

When the disconnecting switch assembly 11 is mounted in the underhung position on cross arms which are carried by a pole and the lineman is required to apply the auxiliary circuit interrupter 32 from a position on the pole, he has only a limited angle within which to work. The provision of the elongated opening 37, together with the proper positioning and design of the combination guide and anchor member 41, makes it possible for the lineman to apply readily the auxiliary circuit interrupter 32 at the end of the live line stick 33 in the proper shunt position.

It will be observed that the pull ring or eye member 37 projects only a slight distance beyond the switch blade 28. This is illustrated more clearly in Figure 6. One reason for this is to permit the prong 36 to operatively enter the elongated opening 37' and engage the pull ring or eye member 37 after only a slight travel of the inner insulating sleeve 38. A minimum portion of the travel of theinner insulating sleeve 38 then is used up in properly positioning the auxiliary circuit interrupter 32 in operative shunt position. This is important when it is recalled that the contacts within the auxiliary circuit interrupter 32 arcsep'arated after the inner insulating sleeve 38 has moved to the distance indicated at 43. In this position the distance indicated at 42 must be such that there is no likelihood of the arc restriking.

The details of the construction of the disconnecting switch assembly 11 are shown more clearly in Figures 5l1 of the drawings to which reference now will be had. It will be understood that the disconnecting switch 11 is typical of the disconnecting switches which can be operated through the agency of the auxiliary circuit interrupter 32 to open position while carrying load current.

It will be recalled that the insulators 18 are mounted on plates 17 which are welded to the side flanges 14 of the channel base 12. As shown in Figure 6 bolts 46 project outwardly from the base of the insulators 18 and access thereto is had through openings 47 in the flat side 13.

In Figures 5 and 8 it will be observed that the switch blade 28 comprises a pair of blade members 48-48 which are formed of suitable good conducting material such as copper and that they are pivoted about the pivot.

' axis 27 by means of a bolt 49 which extends through both;

of the blade members 48 and also through the hinge member 26. They are arranged to engage opposite sides: of the contact member 29 which is in the form of a. tongue as shown in Figures 9 and 11.

It is desirable to provide for limiting the movement of the switch blade to different open positions. For this purpose a stop shoulder 50 is provided on the hinge: member 26 as shown in Figure 6 and is arranged to be: engaged by a removable stop pin 51, Figure 8, which extends through suitable apertures 52 in the blade members. 48. At the ends of the pin C-snap washers 53 areprovided which facilitate the removal of the pin 51 when it is desired to permit the switch blade 28 to move past the 90 position and into engagementwith stop shoulders 54. Thus, when the pin 51 is removed, it is possible to swing the switch blade 28 further until the edges of the blade members 48 engage the stop shoulders 54 in which position the switch blade 28 has been swung through 160 from the switch closed position.

It is desirable to provide for holding the switch blade 28 in the 160 open position by the application of means in addition to the friction between the blade members 48 and the hinge member 26. Advantage is taken of the removal of the stop pin 51 and the freeing of at least one of the apertures 52 for receiving a ball 55 located in a suitable socket 55', Figure 10, in the hinge member 26. A coil compression spring 56 biases the ball 55 outwardly and it is located, as shown in Figure 6, in such position that it interfits with one of the apertures 52 when the switch blade 28 is swung to the 160 open position. It will be understood that the outer edges of the socket 55 are peened over to hold the ball 55 in position therein. The socket 55' is located at the same distance from the pivot 27 that the stop pin 51 is located in order to permit the aperture 52 to register with the ball 55.

As pointed out, a pair of blade members 48--48 is employed. In order to rigidify them intermediate their ends they are deformed outwardly as indicated at 57. Adjacent their upper ends they are flared outwardly as indicated at 48, Figure 11, for the purpose of engaging the contact member 29 even though they may be some what out of alignment therewith. The flared out portions 58 are provided on both sides of the switch blade 48 to provide for interchangeability and to rigidify their upper ends. Similar flared out portions can be formed at the lower ends of the switch blades 48 symmetrical with the stop pin apertures 52 for rigidifying the switch blades 48 adjacent the pivot 27.

It will be observed that the upper ends 59 of the blade members 48 project beyond the contact member 29. It is desirable to provide for biasing the blade members 48 toward each other in order to provide good contact engagement between them and the contact member 29. For this purpose a tension member 60 in the form of a.

members 48 and beyond 'theouter sides thereof as indi-.

cated in Figure 8. At the outer ends of the tension member 60 conical Washers 61'are secured andunclerneath them conical compression springs 62.are prvided to react between the outer sides of'th'e upper ends 59 and the inner sides of the conical washers 61; A stop member in the form of asleeve 63 surrounds the tension member 60 and limits themovement of the upper ends 59 toward each' other to a position slightly less than the thickness of the contact member 29. Thus, when the blade members 48 are moved to the switch closed position, it is only necessary to spread the ends 59 a slight distance apart to permit thefull application of the spring tension applied bythe springs 62;

It is desirable that the conical Washers 61 be employed to overlie the conical springs 62. One reason for this is to reduce the likelihoodof the bow contact'mcmber 40 becoming entangled with the mechanism which biases the ends 59 of the blade-members 48' into contact engagement with the contact member 29. When the bow contact member 40 engages the conical washers 61, it tends to glance away or be warded off. Another reason for the conical washers 61 is to provide a generally spherical configuration on the side of the upper terminal assembly 19 and the upper end of the switch blade 28 so as to reduce sharp corners and, in effect, provide a sphere gap arrangement when the switch blade 28 is swung to the open position.

It is desirable to provide for locking the switch blade 28 in the closed position in order to avoid its being opened when the disconnecting switch assembly 11 is subjected to the flow of short circuit current. For this purpose a keeper 66 is formed integrally with the contact member 29 as shown more clearly in Figure 9. As there shown a rib 66' is. provided on the rear side of the keeper 66. Cooperating with the keeper 66 isa latch 67, Figure 6', which is pivoted on a pin. 68 between the blade members 48. The latch 67has a hook 69 which overlies the backside of the keeper 66 and the rib 66'. The hook 69 cooperates with the keeper 66 to prevent the inadvertent opening of the switch blade 28.

With a view to prying the switch blade 28 out of engagement with the contact member 29 the latch 67 is provided withan arm 70 which overlies the front side of the keeper 66. It will be understood that the upper end of the arm 70, when rotated into engagement with the front side of the keeper 66 acts to move the switch blade 28 outwardly away from the contactmember 29. The latch 67 is biased to the latching position by means of a coil spring 71, Figure 8, one end of which is secured to the latch 67 while the other end 72, Figure 6, is hooked over one of the blade members 48. The spring 71 acts to bias the latch 67in a counterclockwise direction as viewed in Figure 6. The latch 67 has a depending nose portion 73 that is' arranged to be engaged by a detent 74 which is formedintegrally with the pull ring or eye member 37, the latter being pivotally' mounted on a rivet 75, Figure 8, which extends through both of the blade members 48. It will be understood that, when the prong 36 enters the pull ring or eye member 37 and longitudinal force is applied to the live line stick 33, the detent 74 will be rocked'in a counterclockwise direction as viewed in Figure 6, together with the pull ring or eye member 37. This is accompanied by a rocking movement of the latch 67 in the opposite direction, bringing the arm 70 intoengagement with the front side of the keeper 66. By sufiicient rocking movement of the pull ring or eye member 37, the switch blade28 is pryed away from the contact member 29; During this operation the spring 71 is further tensioned. When the operating force applied tothe pull ring. or eye member 37 is released, this spring. acts to restore the latch 67 and pull ring or eye member. 37 to. the positions shown in Figure 6 of the drawings.

Reference has been made hereinbefore to the combination guideand anchor member 41 to which the bow con tact member 40 is connected. Also it has been pointed outthat the combination guide and anchor member 41 functions to direct the blade members 48 into proper contact engagement with the contact member 29 as illustrated in Figure 11. As shown here and in Figure 9 the combination guide and anchor member 41 is provided with horns 78 at opposite ends of a central portion 79 which is arranged to be secured by rivets 80 to the lower end of the terminal pad 21. Preferably the horns 78 are symmetrically arranged and the entire combination guide and anchor member 41 is a one piece casting.

The forward sides of the horns 78 are provided with.

On the rear sides of the horns 78 there are anchor surfaces 83 formed which are arranged to be engaged by' the'bow contact member 40 of the auxiliary circuit interrupter 32. The horns at their outer ends are turned rearwardly suificiently far so as to reduce to a minimum the likelihood of the bow contact member 46 inadvertently slipping out of engagement with the anchor surfaces 83, it being understood that one or the other of these.

anchor surfaces will be engaged depending upon the sidefrom which the operator or lineman chooses to operate" the switch blade 28 to the open position.

It is desirable that the guiding surfaces 81 on the:- horns 78 be spaced sutficiently far in advance of theouter end of the contact member 29 that the desired guid-- ing action of the blade members 48 into engagement with the contact member 29 be provided. At the same time the anchor surfaces 83 preferably are spaced, as in-- dicated at 84, from the outermost portions of the guiding surfaces 81 to such an extent that the bow contact member 40 is properly positioned to permit the extension of the inner insulating sleeve 38 to the position indicated at 43, Figures 2 and 4, where the break distance indicated at 42 between the switch blade 28 and the nearest point on the upper terminal assembly 19 is such that the arc cannot restrike after the circuit has been interrupted by the opening of the contacts within the auxiliary circuit interrupter 32. Preferably the distance 84 is substantially greater than the thickness, indicated at 85 in Figure 9, of the anchor horns '79 in a direction measured parallel to the length of the switch blade 28 in closed position.

It will be observed that the horns 78 of the combination guide and anchor member 41 extend laterally beyond the outer end of the contact member 29 a substantial distance,.as indicated at 86 in Figure 9. After the switch blade 28 leaves the contact member 2 9 and has moved an appreciable distance away from the upper terminal as sembly 19, the nearest energized point on this terminal assembly, aside from the part of the auxiliary circuit interrupter connected thereto, to the switch blade 28 is the outer end of one or the other of the horns 78. Since the outer ends of these horns are generally convex, they, in effect, provide a sphere gap effect insofar as the upper terminal assembly 19 is concerned. This avoids the concentration of electrostatic stress at any particular point or edge and generally reduces the tendency to are over after the flow of current has been interrupted by the auxiliary circuit interrupter 32.

The physical relationship between the contact member 29 and pull ring or eye member 37 is important. As shown more clearly in Figure 6 of the drawings the combination guide and anchor .ember 41 is positioned between the horizontal planev containing the contact member 29 and the horizontal plane containing the pull ring or eye member 37. Further, the keeper 66 extends from the contact member 29 toward the hinge end of the switch blade 28 and the latch 67 is located on the same side of the contact member 29 that the keeper 66 is located. This particular relationship facilitates the operation, previously described, of the auxiliary circuit interrupter 32 first to swing the switch blade 28 through the required distance and then to effect the opening of the contact in the auxiliary circuit interrupter 32 after the switch blade 28 has been moved to this position where there is no likelihood of the are being restruck after the current flow has been interrupted.

Another embodiment of the invention is shown in Figures 12-19 of the drawings and reference now will be had to that embodiment. Here the switch blade construction as indicated at 28 and described hereinbefore is employed in conjunction with the contact member 29 on the upper terminal assembly 19. In the modified construction the latch and pryout mechanism has been modified to provide improved operating characteristics.

It will be observed that the contact member 29 is provided with a depending keeper 87 which extends toward the pivot axis 27 of the switch blade 28. The keeper 87 is somewhat different in configuration than the keeper 66 previously described. It is provided that a fiat latching surface 88 on one side and a pry out surface 89 on the opposite side. Between the surfaces 88 and 89 is an inclined striker surface 90 which is arranged, as will be described hereinafter, to deflect automatically a latch, shown generally at 91, when the switch blade 28 is swung to the switch closed position as shown in Figure 13.

The latch 91 is positioned between the blade members 48-48 and it has a pair of oppositely extending integrally formed trunnions 92 which extend through openings 93 in the blade member 48-48. Formed integrally with the latch 91 is a hook 94 that is arranged in the closed position of the switch blade 28 to overlie the latching surface 88 of the keeper 87 as shown in Figures 13 and 15, for example. On the other side of the latch 91 from the hook 94 is an integrally formed arm 95 which is provided with a curved end surface 96 that is arranged, as shown in Figures 16 and 18, to bear against the pry out surface 89 on rocking of the latch 91 to force the switch blade 28 out of the switch closed position shown in Figures 13 and 15. Between the hook 94 and arm 95011 the latch 91 is a laterally extending boss 97 against which one end 98 of a spring finger, shown generally at 99, bears to bias the latch 91 to the latched position. In Figures 15 and 16 of the drawings it will be noted that the spring finger 99 biases the latch 91 in a counterclockwise direction and, as shown in Figure 15, normally serves to hold the hook 94 in overlying relation with respect to the latching surface 88.

The latch 91 is provided with a depending nose portion 100 which extends toward the pivot axis 27 of the switch blade 28 and has a surface 101 that is arranged to be engaged by a curved end surface 104 of a detent 105 which can be rocked in a counterclockwise direction, as viewed in Figures 15 and 16 of the drawings, to swing the latch 91 from the latched to the unlatched position. The detent 105 is formed integrally with a pull ring that is shown, generally, at 106. Like the latch 91, the pull ring 106 is positioned between the switch blades 4848. It is provided with apertured bosses 107 at its lowermost portion through which a rivet 108 extends and about which the pull ring 106 rocks. The axis of rotation of thepull ring 106 is indicated at 109 and extends through the center of the rivet 108.

It is desirable that the pull ring 106 be so arranged that there will always be a moment applied about the axis 109 from any position in which the live line stick 33 and prong 36 carried thereby are likely to be located. For this purpose the pull ring 106 is provided with an integral eye portion 110 that is offset from the pivot axis 109 in the direction toward the swinging end of the switch blade 28. Also, the eye portion is positioned laterally of the switch blade members 48-48 in order to permit entrance of the prong 36 therein in the manner described hereinbefore for the pull ring 37. It will be noted that the eye portion 110 has an opening 111 for receiving the prong 36.

The shape of the opening 111 for receiving the prong 36 is important, particularly with respect to the location of the inner surface 112 of the outer rim portion 113 of the eye portion 110. It will be noted that the inner surface 112 is inclined away from the longitudinal axis of the switch blade 28. Referring particularly to Figure 13 of the drawings, if the prong 36 of the live line tool is inserted at the location indicated at 114 and a pull thereon is exerted in the direction indicated by the arrow 115, because of the inclination of the inner surface 112, as described, the prong 36 will tend to shift along this surface to the position indicated at 116 where the pull will be in the direction indicated by the arrow 117. Here it will be realized that the moment applied to the pull ring 106 about its pivot axis 109 is greater when the prong 36 is located in the position indicated at 116 than it is when the prong 36 is in the initial position indicated at 114. In the latter position it will be understood that the moment applied to the pull ring 106 about the pivot axis 109 is substantially less. Since the moment about the pivot axis 109 is greater for the prong 36 located as indicated at 116, a lesser force must be exerted on the live line stick 33 by the operator to unlatch the switch blade 28.

Another advantage results from positioning the eye portion 110 of the pull ring 106 offset from the pivot.

axis 109 in the direction of the swinging end of the switch blade 28. With this arrangement it is possible to apply the prong 36 to the eye portion 110 with the live line stick 33 being located throughout a relatively great range without applying it in a position where there is no moment about the axis 109. In particular the construction is such that the prong 36 cannot be positioned in any location in the opening 111 adjacent the pivot axis 109 where a pull thereon will not be applied at some position having a moment about the axis 109 such that the pull ring 106 will be operated.

Reference to Figure 13 shows that an operating pull can be exerted on the pull ring 106 over a wide range. With the prong 36 located at 116 a pull can be exerted in the directions indicated by the arrows A, B and C, for example. The pull can be exerted in the directions indicated by the arrows D and E with the prong 36 located at 114. When the pull is exerted in any of the directions indicated by the arrows AD, there is a moment about the pivot axis 109 applied to the pull ring 106 which is translated into unlatching movement of the latch 91.

It is desirable to limit the rocking movement of the pull ring 106 about its axis 109. For this purpose a stop pin 120 extends through the switch blades 4848 centrally thereof and through a relatively large opening 121 in the web of the pull ring 106 between the detent 105 and the eye portion 110. The stop pin 120 fits loosely in the opening 121 and the range of movement of the pull ring 106 that is permitted relative to the switch blade 28 is that due to the difference in diameters of the stop pin 120 and opening 121.

It was pointed out hereinbefore that the end 98 of the spring finger 99 bears against the laterally extending boss 97 to bias the latch 91 to the latched position. In Figures 15 and 16 it will be observed that the spring finger 99 is provided with a flattened portion 122 at the end 98 and that this flattened end portion 122 bears against the boss 97. The flattened end portion 122 is provided to prevent the body of the spring finger 99 being interposed between the outer end of the boss 97 and the adjacent inner side of the switch blade 48 and teallow greater manufacturing tolerance in the spacing be tween the switch blades 4848. When the pull ring 106 is swung to the position shown in Figure 19 to the limit of its rocking movement with respect to the switch blade 28, the curved end surface 104 engages the spring finger 99'below the flattened end portion 122. This is permitted by the provision of a recess 104' adjacent the boss 97 which is entered by the curved end surface 104 in its extreme operating position as shown in Figure 19. The lower end 123 of the spring finger 99 extends around one of the bosses 107 and the reverse curved end 124 extends around and is anchored to the stop pin 120. It will be observed that the spring finger 99 ispositioned on one'side of the latch 91 and on the same side of the pull ring 106. Further, it will be observed that the spring finger 99 applies a relatively slight biasing action on the latch 91 as compared to the biasing action that is applied to the pull ring 106 which is provided, in part, by the spring finger 99 on one side and by a second spring finger, shown generally at 125, on the other side.

The other spring finger 125 is shown more clearly in Figures 17 and 18 of the drawings. It will be observed that it is shorter than the spring finger 99 and that it has a flattened end portion 126 which bears against one end of the curved end surface 104. The flattened end portion 12-6 prevents the spring finger 125 from being jammed between the detent 105 of the pull ring 106 and the adjacent inner side of the switch blade 48 and allows greater tolerance in the spacing of the switch blades 484S. In this manner the spring finger 125 biases the pull ring 106 against opening movement. The lower portion 127 of the spring finger 125 extends around the other boss 107 of the pull ring 106 and it has a reverse curved end 128 that is anchored around the stop pin 120.

In describing the operation of the embodiment of the invention shown in Figures l2l9 of the drawings, it will be assumed that the switch blade 23 is in the switch closed position as shown in Figures 13, 15 and 17 of the drawings and also as illustrated, for example, in Figure 1 of the drawings. The bow contact member 40 of the auxiliary circuit interrupter 32 is applied to one of the horns 78 and the prong 36 is inserted in the opening 111 in the eye portion 11b. A longitudinal pull applied to the live line stick 33 in the direction indicated by the :arrow 11.; or the arrow 117, Figure 13, swings the pull ring 106 about the axis 109. The curved end surface 104 is swung into engagement with the adjacent surface 101 of the depending nose portion 100 of the latch 91. As shown in Figures 16 and 17 this action results in swinging the latch hook 94 out of overlying relationship withrespect to the latching surface 88 and moves the curved end surface 96 into engagement with the pry out surface 39 on the other side of the keeper 87. The continued pull on the live line stick 22 forces theswitch blade 23 away from the upper terminal assembly 19 and particularly away from the contact member 29. In this movement the latch '91 swings against the biasing action ofits spring finger 99 which is transmitted through the detent 195 to resist the opening movement of the pull ring 1%.. in addition the opening movement. of the pull ring 106 is resisted by the biasing action of the spring finger 12-5. Thus while both spring fingers 99 and 125 act to bias the pull ring 106 against opening movement, only the spring finger 99 reacts against the latch 91. Finally the curved end surface 1&4 of the detent 05 picks up both spring fingers 99 and 125, as shown in Figure 19, and a continued pull on the live'line stick 33 swings the switch blade 28 to the full open position.

When the switch blade 28 is to be swung to the switch closed position, the prong 36 is inserted in the opening 111 andthe switch blade 23 is swung to the switch closed position. When the hook 94'engages the inclinedstriker surface 90 on the lower end of the keeper 37, the; latch 91 is deflected automatically against the biasing action of 12 the spring finger 99 until the hook 94 clears the lower end of'the keeper 87, whereupon it is swung automatically to the latched position as shown in Figure 15 where the sleeve 63 engages a stop surface 129 abovethe contact isrequired to unlatch it. However, it is desirable that a relatively great force be applied between the pull ring 106 and the switch blade 28 in order to maintain the break distance 42, Figures Zand 4. This is accomplished by the spring finger 125 reacting directly against the pull ring 106 and by the spring finger 99 acting indirectly on the pull ring 106 through the latch 91 against the curved end surface 104. As soon as the blade members 48-48 leave the contact member 29, the action of the spring fingers 99 and 125 is to swing the switch blade 28 relatively toward the pull ring 106 and away from the upper terminal assembly 19.

There is another advantage of the relatively great biasing action against the pull ring 106 applied by the spring fingers 99 and 125. Should the lineman inadvertently lose his hold on the live line stick 33 with the prong 36 engaged in the eye portion of the pull ring 106, the weight of the parts attached to the prong 36 is insufficient to rock the pull ring 106 and thereby the latch 91 to unlatched position.

Referring to Figure 15, it will be noted that the curvedend portion 104 of the pull ring 106 engages the surface 101 on the latch 91 at a location where maximum leverage is applied to initiate its movement to the unlatched position. Further rocking of the pull ring 106 toward the unlatching position reduces the lever ratio as the curved end portion 104 rides along the surface 101 toward the pivot axis of the latch 91 through the trunnions 92. Thus a minimum of travel indicated at 43, Figures 2 and 4, of the inner sleeve 38 relative to the outer sleeve 39 is used in unlatching the switch blade 28 and the required gap distance 42 can be maintained while sufficient initial leverage is available to overcome friction at the latching surfaces.

Since certain further changes can be made in the foregoing constructions and different embodiments of the invention can be made without departing from the spun and scope thereof, it is intended that all matter shown in the accompanying drawings and described hereinbefore shall be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

1. A disconnecting switch comprising, in combination,

a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch pivoted to said switch blade having a hook on one side overlying one side of saidkeeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted to said switch blade between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said book out of latching position and said arm into engagement with said other side ofsaid keeper to pry said switch blade out of engagement with said-contact member.

2; A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation havinga hinge-member carried by one terminal and a con.

tact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade comprising a pair of elongated blade members pivoted to said hinge member for movement into and out of engagement with opposite sides of said contact member, a latch pivoted between said blade members having a hook on one side overlying one side of said keeper and anarm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted between said blade members between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member.

3. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having -a hinge member carried by one terminal and provided with a stop shoulder and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade comprising a pair of elongated 'blade members pivoted to opposite sides of said hinge member for movement into and out of engagement with said contact member, a removable stop pin extending transversely of said blade members through an aperture in at least one of them for engaging said stop shoulder and limiting the opening movement of said switch blade, a spring pressed stop member carried by said hinge member for entering said aperture when said stop pin is removed and said blade is swung past said stop shoulder to hold the same in such position, a latch pivoted to said switch blade having a hook on one side overlying one side of said'keeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted to said switch blade between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said book out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member.

- 4. A disconnecting switch comprising, in combination, a pairof line terminals mounted in insulated spaced relationwith a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to .said hinge member for movement into and out of engagement with said contact member, and a combination guide and anchor member secured to said other terminal and having a guide surface on the front side extending beyond said contact member for directing said switch blade into operative engagement therewith and an anchor surface on the rear side spaced from said guide surface in a direction parallel to the path of said switch blade a distance substantially greater than the thickness of said anchor member in a direction parallel to the length of said switch blade in closed position.

5. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insul-atedspaced relation with a hinge member carried by one terminal and a contact member oarried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a combination guide and anchor member secured to said other terminal between said contact member and said hinge member and having a guide surface on the front side extending beyond said contact member for directing said switch blade into operative engagement therewith and an anchor surface on the rear side spaced from said guide surface in a direction parallel to the path of said switch blade a distance substantially greater than the thickness of said anchor member in a direction parallel to the length of said switch blade in closed position, a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted to said switch blade between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member.

6. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, and a combination guide and anchor member secured to said other terminal between said contact member and said hinge member having rearwardly turned horns on opposite sides of said switch blade, each horn lraving a guide surface on the front side extending beyond said contact member for directing said switch blade into operative engagement therewith and an anchor surface on the rear side spaced from said guide surface in a direction parallel to the path of said switch blade in a distance substantially greater than the thickness of the horn in a direction parallel to the length of said switch blade in closed position.

7. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade comprising a pair of elongated blade members pivoted to opposite sides of said hinge member for movement into and out of engagement with opposite sides of said contact member and projecting beyond the same, a tension member extending through the projecting ends of said blade members and connected thereto through spring means to bias the same into contact engagement with opposite sides of said contact member, a stop member between said blade members limiting the movement thereof toward each other under the influence of said spring means when said blade members are out of engagement with said contact member, a latch pivoted between said blade members having a hook on one side overlying one side of said keeper and an arm on the other side overlying the other side of said keeper and 9. depending nose portion, a spring reacting between said switch blade and said latch and biasing the latter to latching position, and a pull ring pivoted between said blade members between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member.

8. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a con tact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade comprising a pair of elongated blade members pivoted to opposite sides of said hinge member for movement into and out of engagement with opposite sides of said contact member and projecting beyond the same, a tension member extending through the projecting ends of said blade members and connected thereto through conical compression springs to bias the same into 6011},

' tact engagement with opposite sides of said contact member, a conical washer secured to each end of said tension member and overlying the respective conical spring and reacting thereagainst, a stop member between said blade members limiting the movement thereof toward each other under the influence of said springs when said blade members are out of engagement with said contact member, a latch pivoted between said blade members having a hook on one side overlying one side of said keeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring reacting between said switch blade and said latch and biasing the latter to latching position, and a pull ring pivoted between said blade members between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said book out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member.

9. A disconnecting switch comprising, in combination, a support channel having the flat central portion adapted to engage flatwise with cross arm support means and a pair of support plates extending across and secured to the side flanges thereof in spaced relation, an insulator secured at one end to each support plate and carrying a line terminal at the other end, a hinge member carried by one line terminal and a contact member carried by the other, and a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member.

10. A disconnecting switch comprising, in combination, a support channel having the flat central portion adapted to engage flatwise with cross arm supportmeans and a pair of support plates extending across and secured to the side flanges thereof in spaced relation, an insulator secured at one end to each support plate and carrying a line terminal at the other end provided with a laterally extending terminal pad carrying conductor clamping means including bolts extending outwardly therethrough with the heads on the side nearer to said support channel, a hinge member carried by one line terminal and a contact member carried by the other, and a switch blade pivoted to said hinge member for movement into and out'of engagement with said contact member.

11. A disconnecting switch comprising, in combination, a support channel having the flat central portion adapted to engage flatwise with cross arm support means and a pair of'support plates extending across and securedto the side flanges thereof in spaced relation, an insulator secured at one end to each support plate and carrying a line terminal at the other end, a hinge member carried by one line terminal and a contact member carried by the other, a switch blade pivoted to said hinge member for movement into and out of engagement With said contact member, latch means for latching said switch blade in closed position, a pull ring pivoted to said switch blade between'said contact member and the pivot of said switch blade for unlatching said latch means and swinging said switch blade to open position, and a combination guide and anchor member secured to said other terminal between said contact member and said pull ring and having a guide surface on the front side extending beyond said contact member for directing said switch blade into operative engagement therewith and an anchor surface on the rear side spaced from'said guide surface in a direction parallel to the path of said switch blade a distancesubstantially greater than the thickness of said anchor member in a direction at right angles thereto.

12. A disconnecting switch comprising, in combina tion, a support cl1annel havingtheflat central portion adaptedto engage flatwise withcross arm support means and apair of support plates extending across and secured to the side flanges thereof in spaced relation, an insulator secured at one end to each support plate and carrying a line terminal at the other end provided with a laterally extending terminal pad carrying conductor clamping means including bolts extending outwardly therethrough with the heads on the side nearer to said support channel, a hinge member carried by one line terminal and a contact member carried by the other, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, latch means for latching said switch blade in. closed position, a pull ring pivoted to said switch blade between said contact member and the pivot of said switch blade for unlatching said latch means and swinging said switch blade to open position, and a combination guide and anchor member secured to said other terminal between said contact member and said pull ring and having a guide surface on the front side extending beyond said contact member for directing said switch blade into operative engagement therewith and an anchor surface on the rear side spaced from said guide surface in a direction parallel to the path of said switch blade a distance substantially greater than the thickness of said anchor member in a direction at right angles thereto.

13. A disconnecting switch comprising, in combination, a support channel having the fiat central portion adapted to engage flatwise with cross arm support means anda pair of support plates extending across and secured to the side flanges thereof in spaced relation, an insulator secured at one end to each support plate'and carrying a line terminal at the other end, a hinge'member carried by one line terminal and a contact member carried by the other having a keeper extending toward said hinge member, a switch blade comprising a pair of elongated blade members pivoted to opposite sides of said hinge member for movement into and out of engagement with opposite sides of said contact member, a latch pivoted between said blade members having a hook on one side overlying one side of said keeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted between said blade members between said latch and the pivot of said switch blade and having a detent engaging said nose portion whereby an outward pull onsaid pull ring rocks said detent against said nose portion to swing said hook out of latchingposition and said arm into engagement with said other side of said keeper to pry said switch blade out of engagementwith said contact member.

14. A disconnecting switch comprising, in combina tion, a pair of line terminals mounted in insulated spaced relation including a hinge member carriedby onetermlnal and a contact member carried by the other terminal, a switch blade comprising a pair of elongated blade members pivoted to said hinge member for movement into and out of engagement with said contact member, and a combination guide and anchor member secured to said other terminal and having a guide surface on the front side extending in the direction of blade opening beyond said contact member for directing said blade members into operative engagement therewith and an anchor surface on the rear side, the portion of said combination guide and anchor member extending; in the direction of opening movement of said'switchblade'haviug a reversely turned section at its extreme end extending generally parallel to said portion with said anchor surface therebetween.

15. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spacedrelation includjnga hinge member carried by one terminal and a contact tongue; carried by the other terminal, a switch blade comprisinga pair ot-elongated blade members t r 17 r pivoted to said hinge member for movement into and out of engagement with opposite sides of said contact tongue, latch and pry out means disposed between said blade members intermediate said contact tongue and hinge member including a pull ring to which operating force can be applied to pry said switch blade out of switch closed position and to swing it to open position, and a combination guide and anchor member secured to said other terminal and having divergent guide surfaces on the front side extending in the direction of blade I opening movement beyond said contact tongue for directing said blade members into operative engagement with opposite sides thereof and anchor surfaces on the rear side. r v 16. ,A disconnecting switch comprising, in combination, a pair of line terminalsin insulated spaced relation including a hinge member carried by one terminal and a contact tongue, carried by the other terminal, a switch blade comprising a pair of elongated blade members pivoted to said hinge membenfor movement into and outof engagement with opposite sides of said contact tongue, latch and pry out means disposed between said blade members intermediate said contact tongue and hinge member including a pull ring to which operating force can be applied to pry said switch blade out of switch closed position and towing it to open position, and a combination guide and anchor member secured to said other terminal between said contact tongue and said hinge member and having divergent guide surfaces on the front side extending in the direction of blade opening movement beyond said contact tongue for directing said blade members into operative engagement with opposite sides thereof and anchor surfaces on the rear side, the outer 'end of said contact tongue being beveled and the edges of said blade members engageable therewith being outwardly flared to cooperate with said guide surfaces in directing said blade members into-switch closed position.

17. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member in the form of a tongue carried by the other terminal and provided with a keeper extending toward said hinge member, a switch blade comprising a pair of elongated blade members pivoted to said hinge member for movement into and out of engagement with opposite sides of said contact tongue, a latch pivoted between said blade members having a part on one side overlying one side of said keeper and an arm on the other side overlying the other side of said keeper and a depending nose portion, a spring biasing said latch to position said part in latching position with respect to said keeper, a pull ring pivoted between said blade members intermediate said latch and the pivot of said switch blade including a detent integral therewith engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said part out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of switch closed position, and a combination guide and anchor member secured to said other terminal and having a guide surface on the front side extending in the direction of blade opening beyond said contact member for directing said blade members into operative engagement therewith and an anchor surface on the rear side. 18. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, latch and pry out means on and reacting between said switch blade and said other terminal including a pull ring pivotally mounted on said switch blade for detachably receiving one terminal of an auxiliary circuit interrupter and 18 r operable thereby to unlatch said switch blade and pry the same out of switch closed position, and an anchor member on said other terminal for receiving another terminal of said auxiliary circuit interrupter, said anchor member including a J-shaped part having the longer arm secured to said other terminal and extending therefrom in the direction of opening movement of said switch blade and the shorter arm extending in the opposite direction and way from the path of said switch blade.

19. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, latch and pry out means on and reacting between said switch blade and said other terminal including a pull ring pivotally mounted on said switch blade and cooperating with said latch and pry out means to unlatch said switch blade and pry the same out of switch closed position, -a first spring reacting against said latch and pry out means and biasing the same to latched position and also reacting against said pull ring when it operates said latch to unlatching position, and a second spring reacting against said pull ring and biasing the same against opening movement in addition to the biasing action exerted thereon as aforesaid by said first spring.

20. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, and latch and pry out means intermediate said hinge member and said contact member and on and reacting between said switch blade and said other terminal including a pull ring pivotally mounted on said switch blade about an axis between said hinge member and said contact member and cooperating with said latch and pry out means to unlatch said switch blade and pry the same out of switch closed position, said pull ring having an eye portion offset from its pivot axis toward the swinging end of said switch blade and outwardly thereof with the inner surface of the outer rim portion inclined away from the longitudinal axis of said switch blade whereby a pull exerted by a prong of a live line tool on said inclined surface tends to cause said prong to shift to a position of increased moment about the pivot axis of said pull ring and about the pivot axis of said switch blade on said hinge member.

21. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, latch and pry out means on and reacting between said switch blade and said other terminal including a pull ring pivotally mounted on said switch blade and cooperating with said latch and pry out means to unlatch said switch blade and pry the same out of switch closed position, said pull ring having an eye portion offset from its pivot axis toward the swinging end of said switch blade and outwardly thereof with the inner surface of the outer rim portion inclined away from the longitudinal axis of said switch blade whereby a pull exerted by .a prong of a live line tool on said inclined surface tends to cause said prong to shift to a position of increased moment about the pivot axis of said pull ring, a first spring reacting against said latch and pry out means and biasing the same to latched position also reacting against said pull ring when it operates said latch to unlatching position, and a second spring reacting against said pull ring and biasing the same against opening movement in addition to the biasing action exerted thereon as aforesaid by said first spring;

22. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, a laterally extending boss between said hook and the latch pivot, and a depending nose portion; a pull ring pivoted to said switch blade between its pivot and said latch and having an eye portion for receiving a prong of a live line tool, and a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out or" engagement with said contact member; a first spring finger at one side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said boss on said latch to bias the same to latched position, and a second spring finger at the other side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said detent on said pull ring to bias the same against opening movement.

23. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member; a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, and a depending nose portion; a pull ring pivoted to said switch blade between its pivot and said latch and having an eye portion offset from the pivot of said pull ring toward the swinging end of said switch blade and positioned outwardly thereof with the inner surface of the outer rim portion inclined away from the longitudinal axis of said switch blade whereby a pull exerted by a prong of a live line tool on said inclined surface tends to cause said prong to shift to a position of increased moment about the pivot axis of said pull ring, and a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member; and spring means reacting against said latch to bias the same to latched position and against said pull ring to bias the same against opening movement.

24. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member; a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, and a dependmg nose portion; a pull ring pivoted to said switch blade between its pivot and said latch and having an eye portion for receiving a prong of a live line tool, and a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said book out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member, spring means reacting against 20 said latch to bias the same to latched position, and additional spring means reacting against said pull ring to bias the same against opening movement.

25. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact memher; a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, and a depending nose portion; a pull ring pivoted to said switch blade between its pivot and said latch and having an eye portion otf set from the pivot of said pull ring toward the swinging end of said switch blade and positioned outwardly thereof with the inner surface of the outer rim portion inclined away from the longitudinal axis of said switch blade whereby a pull exerted by 3. prong of a live line tool on said inclined surface tends to cause said prong to shift to a position of increased moment about the pivot axis of said pull ring, and a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member; spring means reacting against said latch to bias the same to latched position, and additional spring means reacting against said pull ring to bias the same against opening movement.

26. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member; a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, a laterally extending boss between said hook and the latch pivot, and a depending nose portion; a pull ring pivoted to said switch blade between its pivot and said latch and having an eye portion for receiving a prong of a live line tool, a detent for engaging said nose portion whereby an out ward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member, and an opening between said eye portion and said detent; a stop pin carried by said switch blade and extending loosely through said opening to limit the swinging movement of said pull ring relative to said switch blade, a first spring finger at one side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said boss on said latchto bias the same to latched position, and a second spring finger at the other side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said detent on said pull ring to bias the same against opening movement.

27. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member carried by the other terminal and having a keeper extending toward said hinge member, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member; a latch pivoted to said switch blade having a hook on one side overlying one side of said keeper, an arm on the other side overlying the other side of said keeper, a laterally extending boss between said hook and the latch pivot,

and a depending nose portion; a pull ring pivoted to said switch blade between its-pivot and said latch and having an eye portion offset from -the pivot of said pull ring toward the swinging end of said switch blade and positioned outwardly thereof with the inner surface of the outer rim portion inclined away from the longitudinal axis of said switch blade whereby a pull exerted by a prong of a live line tool on said inclined surface tends to cause said prong to shift to a position of increased moment about the pivot axis of said pull ring, a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position and said arm into engagement with said other side of said keeper to pry said switch blade out of engagement with said contact member, and an opening between said eye portion and said detent; a stop pin carried by said switch blade and extending loosely through said opening to limit the swinging movement of said pull ring relative to said switch blade, a first spring finger at one side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said boss on said latch to bias the same to latched position, and a second spring finger at the other side of said pull ring extending around its pivot with one end reacting against said stop pin and the other end reacting against said detent on said pull ring to bias the same against opening movement.

28. A disconnecting switch comprising, in combination, a support channel having the flat central portion adapted to engage flatwise with cross arm support means and means providing a pair of longitudinally spaced supporting surfaces substantially at the level of the edges of the side flanges of said support channel and facing oppositely to that surface of said flat central portion engageable with said cross arm support means, an insulator secured at one end to each support surface and carrying a line terminal at the other end, a hinge member carried by one line terminal and a contact member carried by the other, and a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member.

29. A disconnecting switch comprising, in combination, a support channel having the fiat central portion adapted to engage flatwise with cross arm support means and means providing a pair of longitudinally spaced supporting surfaces substantially at the level of the edges of the side flanges of said support channel and facing oppositely to that surface of said fiat central portion engageable with said cross arm support means, an insulator secured at one end to each support surface and carrying a line terminal at the other end provided with a laterally extending terminal pad carrying conductor clamping means including bolts extending outwardly therethrough with the heads on the side nearer to said support channel, a hinge member carried by one line terminal and a contact member carried by the other, and a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member.

30. A circuit isolating device comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal, a keeper secured to said other terminal, an elongated rigid conducting member pivoted to said hinge member for movement into and out of engagement with said contact member, combination guide and anchor means secured to said other terminal and having a guide surface on the front side extending beyond said contact member for directing said elongated rigid conducting member into operative engagement therewith and an anchor surface on the rear side for detachably receiving one terminal of an auxiliary circuit interrupter, said anchor surface being spaced from said guide surface in a direction parallel to the path of said elongated rigid conducting member a distance substantially greater than the thick ness of said anchor member in. a direction parallel to the length of said elongated rigid conducting member in closed position, a latch pivoted to said elongated rigid conducting member having a hook on one side overlying said keeper in latching position and a depending nose portion, a spring biasing said latch to latching position, and a pull ring pivoted to said elongatedrigid conducting member between said latch and said hinge member for detachably receiving another. terminal of said auxiliary circuit interrupter, said pull ring having a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said book out of latching position on movement of said other terminal of said auxiliary circuit interrupter away from said one terminal thereof to move said elongated rigid conducting member out of engagement with said contact member.

31. A disconnecting switch comprising, in combination, a pair of line terminals in insulated spaced relation having a hinge member carried by one terminal and a contact member and a keeper carried by the other terminal, a switch blade comprising a pair of elongated blade members pivoted to opposite sides of said hinge member for movement into and out of engagement with opposite sides of said contact member and projecting beyond the same, a tension member extending through the projecting ends of said blade members and connected thereto through spring means to bias the same into contact engagement with opposite sides of said contact member, a stop member between said blade members limiting the movement thereof toward each other under the infiuence of said spring means when said blade members are out of engagement with said contact member, combination guide and anchor means secured to said other terminal and having a guide surface on the front side extending beyond said contact member for directing said blade members into contact engagement with said opposite sides of said contact member and an anchor surface on the rear side for detachably receiving one terminal of an auxiliary circuit interrupter, said anchor surface being spaced from said guide surface in a direction parallel to the path of said switch blade a distance substantially greater than the thickness of said anchor member in a direction parallel to the length of said switch blade in closed position, a latch pivoted between said blade members having a hook on one side overlying said keeper in latching position and a depending nose portion, a spring reacting between said switch blade and said latch and biasing the latter to latching position, a pull ring pivoted between said blade member-s between said latch and the pivot of said switch blade for detachably receiving another terminal of said auxiliary circuit interrupter, said pull ring having a detent for engaging said nose portion whereby an outward pull on said pull ring rocks said detent against said nose portion to swing said hook out of latching position on movement of said other terminal of said auxiliary circuit interrupter away from said one terminal thereof to move said switch blade out of engagement with said contact member.

32. A circuit isolating device comprising, in combination, a pair of line terminals in insulated spaced relation including a hinge member carried by one terminal and a contact member carried by the other terminal, an elongated rigid conducting member pivoted to said hinge member for movement into and out of engagement with said contact member, latch means on and reacting between said elongated rigid conducting member and said other terminal including a pull ring pivotally mounted on said elongated rigid conducting member for detachably receiving one terminal of an auxiliary circuit interrupter and operable thereby to unlatch said elongated rigid conducting member from said other terminal, and an anchor member on said other terminal for receiving another terminal of said auxiliary circuit interrupter, said References Cited in the file of this patent UNITED STATES PATENTS 473,132 Soden Apr. 19, 1892 24 Hoffman Aug. 1, 1893 Froland June 4, 1940 Crabbs et a1. Dec. 10, 1940 Lindell Mar. 2, 1954 Cowan June 1, 1954 Gilliland Aug. 20, 1957 Turnham Aug. 20, 1957 

